150 entries under hard topic. ×

1
tough nut to crack(expression, adjective, idiom, mean)
1
unadaptable(resolute, rigid, inflexible, strict)
1
uncontrite(adjective, tough, harsh, cruel)
1
unemotional(adjective, mean, tough, harsh)
1
ungracious(adjective, severe, sharp, nasty)
1
unimpressible(adjective, mean, tough, harsh)
1
unkind(adjective, animal, mean, severe)
1
unrepenting(adjective, tough, harsh, cruel)
1
wicked(adjective, severe, evil, sharp)
0
abusive(adjective, severe, sharp, nasty)
0
comfortless(adjective, severe, sharp, nasty)
0
dense(adjective, strong, tough, sturdy)
0
discourteous(adjective, severe, sharp, nasty)
0
ferric(adjective, strong, tough, sturdy)
0
ferrous(adjective, strong, tough, sturdy)
0
frigid(adjective, mean, harsh, cold)
0
hairy(adjective, severe, sharp, nasty)
0
hard-and-fast(resolute, rigid, inflexible, strict)
0
hatchetjob(adjective, mean, harsh, cold)
0
killer instinct(expression, adjective, mean, harsh)
11 years ago|18k views|share |citing 
APASmart Define. (2015). relentless thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/relentless/thesaurus/synonyms
ChicagoSmart Define. 2015. "relentless thesaurus" https://smartdefine.org/relentless/thesaurus/synonyms (accessed September 25, 2026).
HarvardSmart Define 2015, relentless thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/relentless/thesaurus/synonyms>.
MLASmart Define. "relentless thesaurus" 24 June 2015. Web. 25 September 2026. <https://smartdefine.org/relentless/thesaurus/synonyms>